| The metallurgy manufacturing industry in China has developed rapidly since the 13 th Five-Year Plan,and the innovation capability of manufacturing industry has been enormously ascended.The green,environmental development has become a new trend in the industrial environment.And magnesium alloy plate has a broad range of applications in all sectors as a new material.As a consequence,the high-quality specifications for magnesium board have been continually heightened.Moreover,the magnesium alloy plate in the process of preparation,so that the magnesium plate due to the impact of all kinds of parameters,magnesium plate appears wavy,medium wave and other plate defects,so it is necessary to straighten the magnesium alloy plate,so as to achieve high quality magnesium plate to meet the demands of the development of respective fields.In the classical straightening theory,the neutral layer offset element during the material straightening procedure is always neglected in the construction of the straightening model,which leads to the quality of the straightened material not reaching the ideal standard.Therefore,it is important to study the neutral layer offset of magnesium alloy in the flattening mechanism to increase the straightening stability.This article first of all gives a systematic description of the application of magnesium alloy plates and the issues in the straightening,the state of research in the theory of straightening,and the state of research in the theory of neutral layer offset,and describes the study purpose and research significance of this paper.According to the conventional straightening theories,the computational approach of various parties in the bending of the sheets and the calculation of the choice of the straightening scheme are concluded.In this study,according to the definition feature of magnesium plate in roll straightening,the equation of neutral layer offset of AZ31 B magnesium alloy plate during straightening is derived based on the basic theory of elasticity-plasticity mechanics and the yield criterion of Ca Ba2004 tensile asymmetry,and the effect of temperature to the tensile asymmetry of magnesium alloy is elaborated.By creating a straightening model at room temperature and under the thermodynamic combined model with ABAQUS finite energy model,the variations curves of neutral layer deflection of magnesium alloy plate at various temperatures of straightening were analyzed,and the law of neutral layer deflection of AZ31 B magnesium alloy plate at different straightening temperatures was arrived at,which proves the theory of neutral layer deflection of magnesium alloy plate and proves the theoretical foundation for realizing the optimisation of straightening pattern and enhancing the leveling quality.This report also explored the influence of straightening temperature on the straightening effect of magnesium alloy plate,and depending on the characteristics of ductility and plasticity of magnesium alloy at room temperature and easy to fracture,together with the real straightening scheme,using ABAQUS simulation software to build the dynamic leveling simulation of magnesium alloy sheet at the room temperature and thermal coupling to analyze the change of straightening force at different temperatures,the variation of remnant stress after straightening and flatness analysis,and initially discovered the reasonable straightening scheme of magnesium alloy board.Finally,through the analysis of the theoretical study and finite element simulation,a reasonable neutral layer offset experiment was created,and the viability of the neutral layer offset theoretical and finite element simulation was confirmed through the processing of the results.By AZ31 B magnesium alloy plate straightening theory,we analyze the condition of magnesium plate after straightening,so that we can perfect the straightening pattern and enhance the straightening precision effectively,and provide the theoretical and practical basis for the straightening of magnesium alloy plate. |
PDF Full Text Request